This is a reissue application of our U.S. Pat. No. 3,740,502, issued June 19, 1973, filed Apr. 7, 1972, Application Ser. No. 241,963, assigned to the same assignee as the present application. .Iaddend.
This invention relates to an alarm clock timer, and more particularly to a cam mechanism for actuating a control mechanism such as an alarm vibrator or a switch at a preset time to sound an alarm or turn on a radio.
In devices of this type it has been a common practice to provide a pair of coaxially mounted gear driven cam members with one of the members being axially movable to actuate an alarm or other form of control mechanism. One of the cam members is driven by a timing motor and the other is adjustable so that the position at which the axial actuating movement occurs can be preset. In a mechanism of this type some means such as a spring is provided for urging the axially movable cam member into engagement with the mating cam member in order to insure that the axial actuating movement takes place. As shown in a prior U.S. Pat. No. 3,598,937 to Balchunas dated Aug. 10, 1971, assigned to the same assignee as the present invention, this has been accomplished by a resilient switch blade which normally urges switch contacts to a closed position and also urges an axially movable cam member into engagement with the mating cam member.
As shown in a prior U.S. Pat. No. 2,768,332 to Protzmann et al. dated Oct. 23, 1956, a resilient vibrator arm of an alarm clock has also been utilized for urging an axially movable cam member into mating engagement with its cooperating cam member.
In conventional alarm time gear and alarm set cam gear mechanisms such as the one disclosed and illustrated in a prior U.S. Pat. No. 2,702,450 to Gummersall dated Feb. 22, 1955, a spring 30 is provided for moving a cam gear member 22 axially toward cam gear member 24. At a preset alarm time a cam follower 38 of gear 24 moves into a complemental slot 40 in gear 22, and spring 30 axially moves cam gear 22 toward cam gear 24. A timing motor continuously rotates a gear 22 and rotation of the gear slowly moves the cam finger 38 on the edges of the slot 40 to gradually separate the cam gear members 22 and 24 to thereby slowly reset the cams. It can be appreciated that higher torque loads are applied to the timing motor during such a resetting movement than would normally be applied to the motor for simply rotating the hands of the clock.
In our co-pending application, Ser. No. 196,479, filed Nov. 8, 1971, .Iadd.now U.S. Pat. No. 3,721,087, .Iaddend.and assigned to the same assignee as the present invention, there is disclosed a digital clock, and more particularly, a mechanism for driving the minutes, tens of minutes, hours and tens of hours display indicators for a digital clock. Such a mechanism requires a higher torque motor than would be required for merely driving the hands of a clock, and thus with the addition of a radio alarm mechanism to such a digital clock it becomes particularly desirable to provide a radio alarm mechanism which does not appreciably add to the torque requirements of the motor.
This invention is concerned with an improved cam gear mechanism for a radio alarm clock or other alarm clock which has very low torque requirements. It is also an object of our invention to provide a cam mechanism which may be readily combined with a digital clock of the type disclosed in the above-mentioned co-pending application.